Sony has managed to sell a total of 321,407 PlayStation Vitas on December 17 (the day it was launched in Japan) and 18, according to Japanese video game magazine Famitsu [JP]. This pretty solid number means that big S has sold about 46% of its initial shipment of Vitas (which is rumored to be around 700,000 units) in 48 hours.

In comparison, back on December 12, 2004 (the day the PSP was launched), Sony sold a total of 166,074 units in 24 hours, while Nintendo was able to sell a total of 371,326 3DS systems in the first 48 hours after launch in Japan on February 26 this year.

The positive sales figures were partly overshadowed today by early reports from Japanese Vita users complaining about technical problems. Sony Computer Entertainment reacted by issuing an official apology on its website and pushing out a software update to version 1.5.